ACTIVELY EXPLOITED
CVE-2021-33766: Microsoft Exchange Server Information Disclosure
| Vendor | Microsoft |
|---|---|
| Product | Exchange Server |
| Actively exploited | Yes |
| Added to CISA KEV | 18 Jan 2022 |
| CISA federal deadline | 1 Feb 2022 |
| Weakness (CWE) | CWE-287 |
Required action (CISA's text)
Apply updates per vendor instructions.
Description (NVD)
Microsoft Exchange Server contains an information disclosure vulnerability which can allow an unauthenticated attacker to steal email traffic from target.
SOURCES
Other Microsoft flaws
- patchtuesday:2026-11: Vulnerability in Microsoft
- CVE-2026-124194: Microsoft Office Outlook Missing User Interaction for Potentially Unsafe Action Vulnerability
- CVE-2026-96951: Microsoft Windows Command Injection Vulnerability
- CVE-2026-65660: Microsoft SharePoint Code Injection Vulnerability
- CVE-2026-85880: Microsoft Windows Heap-Based Buffer Overflow Vulnerability
Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.